Panax ginseng C. A. Mayer (hereinafter, abbreviate to ‘ginseng’) is a generic ginseng plant of the Arliaceae family. Panax ginseng has been used for medicinal purposes in China since B.C. and has been employed for medicinal purposes or as a trade item in Korea since the era of the Three Kingdoms. Panax ginseng is now widely used for preparation of oriental medicines or health supplements used for a variety of applications.
Ginseng generally includes about 3 to 6% of saponin-like materials called ginsenosides as species-specific ingredients and the ginsenosides are major physiological active materials and may be classified into panaxadiol (PD), panaxatriol (PT) and oleanane based ginsenosides. About 33 species of ginsenosides have recently been reported.
PD based saponin and PT based saponin have different functions in vivo. PD based saponin including ginsenoside Rb1 as a representative example, is known to exhibit inhibitory action on the central nervous system, in turn accomplishing tranquilization, neuroleptic, analgesic, anti-convulsive and/or hypotensive effects, influence upon papaverine content, or the like. On the other hand, PT based saponin including ginsenoside Rg1 as a representative example, is known to excitedly react to the central nervous system, thus exhibiting anti-fatigue activity. Therefore, it is assumed that, if saponin components in ginseng having opposing activities are separated or reinforced, pharmacological activity of ginseng may be more efficiently attained. However, most recent studies into ginsenosides are directed to a method for increasing contents of trace ingredients present in ginseng (U.S. Pat. No. 7,371,416), use of ginsenosides for treatment of particular diseases (WO 01/056585), or the like. However, research and investigations into techniques to improve efficacies of ginsenosides Rg1 and Rb1 showing opposing activities, respectively, have not been sufficient.
Korean Patent No. 620,107 discloses a process for production of ginsenoside Rg2 as a specific component of ginseng saponin by treating a water extract or an alcohol extract of ginseng using lactic acid. Korean Patents Nos. 517,128 and 192,678 disclose variation in yield of saponin depending upon alcohol concentration or extraction temperature in consideration of thermal stability when the saponin is extracted from ginseng. However, all of these techniques adopt petroleum ether as an extraction solvent, thus being unsuitable for foods or medical use. In addition, the foregoing arts neither disclosed nor suggested methods for preparing an extract fraction reinforced with ginsenoside Rg1 or Rb1.
Moreover, although Korean Patent No. 0,444,394 describes a method for preparation of an extract having high saponin content through adsorption using an adsorption resin, a process of obtaining an extract fraction reinforced with specific saponin components is not disclosed or suggested therein.